Conventional vehicle power steering systems, such as ones used in automobiles and light trucks, use a continuously operating hydraulic pump and a twistable steering torsion bar connected at one end to a vehicle steering wheel and connected at the other end to the pinion gear of the steering system. A driver turning the vehicle steering wheel results in twisting of the steering torsion bar which physically opens and closes hydraulic flow-control valves which results in high pressure fluid flowing to one side or the other side of a hydraulic piston which moves the wheel tie rods to turn the vehicle wheels. Unsuccessful attempts at designing an electric-controlled hydraulic system, which involved the steering torsion bar in the valve control loop to produce a pressure level, are known.
Still, scientists and engineers continue to seek improved vehicle power steering systems.